Family History of Diabetes and Clinical Characteristics in Children at Diagnosis of Type 1 Diabetes-A Swedish Population-Based Study

OBJECTIVE

To compare the prevalence of parental diabetes between children with and without type 1 diabetes (T1D), and to compare clinical characteristics at diagnosis of T1D in children with, versus without, a family history of diabetes.

RESEARCH DESIGN AND METHODS

Parental diabetes among children with T1D was compared with a general population cohort. Clinical characteristics were compared by family history of diabetes in parents and grandparents of 3,603 children with T1D using relative risk (RR) and ANOVA.

RESULTS

Children with T1D more often had parents with type 2 diabetes (T2D) (RR 1.88; P < 0.001) than did children without diabetes. Children with T1D and a family history of T2D were more likely to be overweight or obese (P = 0.002).

CONCLUSIONS

A family history of T2D and being overweight may contribute to increased risk of T1D.

HbA1c and biomarkers of diabetes mellitus in Clinical Chemistry and Laboratory Medicine: ten years after

Since its discovery in the late 1960s, HbA_1c has proven to be a major biomarker of diabetes mellitus survey and diagnosis. Other biomarkers have also been described using classical laboratory methods or more innovative, non-invasive ones. All biomarkers of diabetes, including the historical glucose assay, have well-controlled strengths and limitations, determining their indications in clinical use. They all request high quality preanalytical and analytical methodologies, necessitating a strict evaluation of their performances by external quality control assessment trials. Specific requirements are needed for point-of-care testing technologies. This general overview, which describes how old and new tools of diabetes mellitus biological survey have evolved over the last decade, has been built through the prism of papers published in Clinical Chemistry and Laboratory Medicine during this period.

Risk factors for nephropathy in persons with type 1 diabetes: a population-based study

AIMS

Albuminuria is strongly associated with risk of renal dysfunction, cardiovascular disease and mortality. However, clinical guidelines diverge, and evidence is sparse on what risk factor levels regarding blood pressure, blood lipids and BMI are needed to prevent albuminuria in adolescents and young adults with type 1 diabetes.

METHODS

A total of 9347 children and adults with type 1 diabetes [mean age 15.3 years and mean diabetes duration 1.4 years at start of follow-up] from The Swedish National Diabetes Registry were followed from first registration until end of 2017. Levels for risk factors for a risk increase in nephropathy were evaluated, and the gradient of risk per 1 SD (standard deviation) was estimated to compare the impact of each risk factor.

RESULTS

During the follow-up period, 8610 (92.1%) remained normoalbuminuric, 737 (7.9%) individuals developed micro- or macroalbuminuria at any time period of whom 132 (17.9% of 737) individuals developed macroalbuminuria. Blood pressure ≥ 140/80 mmHg was associated with increased risk of albuminuria (p ≤ 0.0001), as were triglycerides ≥ 1.0 mmol/L (p = 0.039), total cholesterol ≥ 5.0 mmol/L (p =  0.0003), HDL < 1.0 mmol/L (p = 0.013), LDL 3.5- < 4.0 mmol/L (p = 0.020), and BMI ≥ 30 kg/m² (p =  0.033). HbA1c was the strongest risk factor for any albuminuria estimated by the measure gradient of risk per 1 SD, followed by diastolic blood pressure, triglycerides, systolic blood pressure, cholesterol and LDL. In patients with HbA1c > 65 mmol/mol (> 8.1%), blood pressure > 140/70 mmHg was associated with increased risk of albuminuria.

CONCLUSIONS

Preventing renal complications in adolescents and young adults with type 1 diabetes need avoidance at relatively high levels of blood pressure, blood lipids and BMI, whereas very tight control is not associated with further risk reduction. For patients with long-term poor glycaemic control, stricter blood pressure control is advocated.

Comparing continuous subcutaneous insulin infusion and multiple daily injections in children with Type 1 diabetes in Sweden from 2011 to 2016-A longitudinal study from the Swedish National Quality Register (SWEDIABKIDS)

OBJECTIVE

This study aimed to compare metabolic control measured as hemoglobin A1c (HbA1c), the risk of severe hypoglycemia, and body composition measured as body mass index standard deviation scores (BMI-SDS) in a nationwide sample of children and adolescents with Type 1 diabetes with continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI), respectively.

RESEARCH DESIGN AND METHODS

Longitudinal data from 2011 to 2016 were extracted from the Swedish National Quality Register (SWEDIABKIDS) with both cross-sectional (6 years) and longitudinal (4 years) comparisons. Main end points were changes in HbA1c, BMI-SDS, and incidence of severe hypoglycemia.

RESULTS

Data were available from 35,624 patient-years (54% boys). In general, HbA1c decreased approximately 0.5% (2-5 mmol/mol) from 2011 to 2016 (p_trend  < 0.001) and the use of CSII increased in both sexes and all age groups. Mean HbA1c was 0.1% (0.7-1.5 mmol/mol) lower in the CSII treated group. Teenagers, especially girls, using CSII tended to have higher BMI-SDS. There was no difference in the number of hypoglycemias between CSII and MDI over the years 2011-2016.

CONCLUSIONS

There was a small decrease in HbA1c with CSII treatment but of little clinical relevance. Overall, mean HbA1c decreased in both sexes and all age groups without increasing the episodes of severe hypoglycemia, indicating that other factors than insulin method contributed to a better metabolic control.

HbA1c level as a risk factor for retinopathy and nephropathy in children and adults with type 1 diabetes: Swedish population based cohort study

OBJECTIVE

To evaluate if the lowest target level for glycated haemoglobin (HbA_1c) of <6.5% is associated with lower risk for retinopathy and nephropathy than less tight control in children and adults with type 1 diabetes.

DESIGN

Population based cohort study.

SETTING

Swedish National Diabetes Registry, 1 January 1998 to 31 December 2017.

PARTICIPANTS

10 398 children and adults with type 1 diabetes followed from diagnosis, or close thereafter, until end of 2017.

MAIN OUTCOME MEASURES

Relative risk (odds ratios) for retinopathy and nephropathy for different mean levels of HbA_1c.

RESULTS

Mean age of participants was 14.7 years (43.4% female), mean duration of diabetes was 1.3 years, and mean HbA_1c level was 8.0% (63.4 mmol/mol). After adjustment for age, sex, duration of diabetes, blood pressure, blood lipid levels, body mass index, and smoking, the odds ratio for mean HbA_1c <6.5% (<48 mmol/mol) compared with 6.5-6.9% (48-52 mmol/mol) for any retinopathy (simplex or worse) was 0.77 (95% confidence interval 0.56 to 1.05, P=0.10), for preproliferative diabetic retinopathy or worse was 3.29 (0.99 to 10.96, P=0.05), for proliferative diabetic retinopathy was 2.48 (0.71 to 8.62, P=0.15), for microalbuminuria or worse was 0.98 (0.60 to 1.61, P=0.95), and for macroalbuminuria was 2.47 (0.69 to 8.87, P=0.17). Compared with HbA_1c levels 6.5-6.9%, HbA_1c levels 7.0-7.4% (53-57 mmol/mol) were associated with an increased risk of any retinopathy (1.31, 1.05 to 1.64, P=0.02) and microalbuminuria (1.55, 1.03 to 2.32, P=0.03). The risk for proliferative retinopathy (5.98, 2.10 to 17.06, P<0.001) and macroalbuminuria (3.43, 1.14 to 10.26, P=0.03) increased at HbA_1c levels >8.6% (>70 mmol/mol). The risk for severe hypoglycaemia was increased at mean HbA_1c <6.5% compared with 6.5-6.9% (relative risk 1.34, 95% confidence interval 1.09 to 1.64, P=0.005).

CONCLUSIONS

Risk of retinopathy and nephropathy did not differ at HbA_1c levels <6.5% but increased for severe hypoglycaemia compared with HbA_1c levels 6.5-6.9%. The risk for severe complications mainly occurred at HbA_1c levels >8.6%, but for milder complications was increased at HbA_1c levels >7.0%.

Interventions using pediatric diabetes registry data for quality improvement: A systematic review

BACKGROUND

Diabetes registries contain vast amounts of data that can be used for quality improvement (QI) and are foundational elements of learning health systems; infrastructure to share data, create knowledge rapidly and inform decisions to improve health outcomes. QI interventions using adult diabetes registries are associated with improved glycemic control, complication screening rates, and reduced hospitalizations; pediatric data are limited.

OBJECTIVE

To evaluate the effects of QI strategies that use pediatric diabetes registry data on care processes, organization of care, and patient outcomes.

METHODS

We searched MEDLINE, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, Google, Google Scholar, Directory of Open Access Journals, and diabetes registry websites for studies that evaluated the impact of QI interventions on diabetes care processes, care organization, or patient outcomes, using pediatric diabetes registry data. Two reviewers independently assessed eligibility, extracted data and assessed the risk of bias.

RESULTS

Twelve studies were included. Most interventions targeted health-care providers and evaluated effects on patient outcomes. Five of nine studies that evaluated hemoglobin A1c found improvements of 0.26% to 0.85% (2.8-9.3 mmol/mol) while four found no difference. Many report positive effects on care processes or organization. Study data could not be combined because of variable study design and outcome measures. Included studies represent a minority of existing registries.

CONCLUSIONS

Pediatric diabetes registries are underused for QI and may facilitate improved care and outcomes. Existing vast amount of pediatric registry data could be used to foster the development of learning health systems and to improve diabetes care and outcomes.

Accuracy of HbA1c as Monitored by External Quality Assessment and Compared With Patient Mean Values

BACKGROUND

The accuracy and trueness of results from a laboratory test, such as the HbA1c test, should not be taken for granted but must be checked continuously. A tool for this is the participation in external quality assessment (EQA) for all laboratories performing the HbA1c-test. An additional possibility to detect changes in trueness is to monitor variations in patient cohort mean or median values that is not explained by changes in treatment or selection of patients.

METHODS

Results reported to an EQA scheme for HbA1c during 20 years have been extracted from Equalis database. The results are compared to current analytical performance specifications (APS) and to the mean HbA1c levels for the Swedish population of persons with type 2 diabetes.

RESULTS

The accuracy of the HbA1c test has improved during the period. The hospital lab methods used in Sweden now fulfil APS agreed by professional organizations in Sweden. The accuracy for point-of-care tests (POCT) methods vary over time and fulfil APS for some periods. The bias found for some of the methods might explain changes seen in patient mean values for HbA1c in Sweden during the period 2007-2017.

CONCLUSIONS

The global standardization of HbA1c has resulted in an improved comparability for HbA1c-results worldwide. But even small variation in trueness for the methods in use might have important impact on mean HbA1c values for cohorts of patients. When a systematic error is observed for a specific method it is therefore essential that manufacturers correct the method without delay.

Low renal replacement therapy incidence among slowly progressing elderly chronic kidney disease patients referred to nephrology care: an observational study

Background

Elderly patients with advanced chronic kidney disease (CKD) have a high risk of death before reaching end-stage kidney disease. In order to allocate resources, such as advanced care nephrology where it is most needed, it is essential to know which patients have the highest absolute risk of advancing to renal replacement therapy (RRT).

Methods

We included all nephrology-referred CKD stage 3b-5 patients in Sweden 2005–2011 included in the Swedish renal registry (SRR-CKD) who had at least two serum creatinine measurements one year apart (+/− 6 months). We followed these patients to either initiation of RRT, death, or September 30, 2013. Decline in estimated glomerular filtration rate (eGFR) (%) was estimated during the one-year baseline period. The patients in the highest tertile of progression (>18.7% decline in eGFR) during the initial year of follow-up were classified as “fast progressors”. We estimated the cumulative incidence of RRT and death before RRT by age, eGFR and progression status using competing risk models.

Results

There were 2119 RRT initiations (24.2%) and 2060 deaths (23.5%) before RRT started. The median progression rate estimated during the initial year was −8.8% (Interquartile range [IQR] - 24.5–6.5%). A fast initial progression rate was associated with a higher risk of RRT initiation (Sub Hazard Ratio [SHR] 2.24 (95% confidence interval [CI] 2.00–2.51) and also a higher risk of death before RRT initiation (SHR 1.27 (95% CI 1.13–1.43). The five year probability of RRT was highest in younger patients (<65 years) with fast initial progression rate (51% in CKD stage 4 and 76% in stage 5), low overall in patients >75 years with a slow progression rate (7, 13, and 25% for CKD stages 3b, 4 and 5 respectively), and slightly higher in elderly patients with a fast initial progression rate (28% in CKD stage 4 and 47% in CKD stage 5) or with diabetic kidney disease.

Conclusions

The 5-year probability of RRT was low among referred slowly progressing CKD patients >75 years of age because of the competing risk of death.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0473-1) contains supplementary material, which is available to authorized users.

National Swedish study of immigrant children with type 1 diabetes showed impaired metabolic control after three years of treatment

AIM

This study examined the clinical status and socio-demographic conditions of children with type 1 diabetes at baseline and after three years of treatment, comparing those born to immigrant parents and Swedish parents.

METHODS

This observational nationwide population-based cohort study used prospectively collected registry data from Swediabkids, the National Quality Registry for Paediatric Diabetes in Sweden from 2000 to 2010. Of the 13 415 children with type 1 diabetes, there were 879 born to immigrant parents. We selected three children born to Swedish parents from the same registry for each immigrant child matching them by gender, age and year of diabetes onset (n = 2627; with 10 control children missing probably due to the matching procedure).

RESULTS

Immigrant children had a higher median glycated haemoglobin level (HbA1c) than their Swedish peers, but there was no difference in the frequency of hypoglycaemia or ketoacidosis between the two cohorts. A linear regression model with HbA1c as a dependent variable showed that insulin units per kilogram of body weight were the main reason for inferior metabolic control.

CONCLUSION

Children with type 1 diabetes born to immigrant parents had inferior metabolic control three years after disease onset compared to children with Swedish born parents. Social family support and educational coping programmes are needed to improve treatment outcomes in immigrants with diabetes.

Benchmarking by HbA1c in a national diabetes quality register--does measurement bias matter?

BACKGROUND

Bias in HbA1c measurement could give a wrong impression of the standard of care when benchmarking diabetes care. The aim of this study was to evaluate how measurement bias in HbA1c results may influence the benchmarking process performed by a national diabetes register.

METHODS

Using data from 2012 from the Norwegian Diabetes Register for Adults, we included HbA1c results from 3584 patients with type 1 diabetes attending 13 hospital clinics, and 1366 patients with type 2 diabetes attending 18 GP offices. Correction factors for HbA1c were obtained by comparing the results of the hospital laboratories'/GP offices' external quality assurance scheme with the target value from a reference method.

RESULTS

Compared with the uncorrected yearly median HbA1c values for hospital clinics and GP offices, EQA corrected HbA1c values were within ±0.2% (2 mmol/mol) for all but one hospital clinic whose value was reduced by 0.4% (4 mmol/mol). Three hospital clinics reduced the proportion of patients with poor glycemic control, one by 9% and two by 4%.

CONCLUSIONS

For most participants in our study, correcting for measurement bias had little effect on the yearly median HbA1c value or the percentage of patients achieving glycemic goals. However, at three hospital clinics correcting for measurement bias had an important effect on HbA1c benchmarking results especially with regard to percentages of patients achieving glycemic targets. The analytical quality of HbA1c should be taken into account when comparing benchmarking results.

Review of 103 Swedish Healthcare Quality Registries

BACKGROUND AND OBJECTIVES

In the past two decades, an increasing number of nationwide, Swedish Healthcare Quality Registries (QRs) focusing on specific disorders have been initiated, mostly by physicians. Here, we describe the purpose, organization, variables, coverage and completeness of 103 Swedish QRs.

METHODS

From March to September 2013, we examined the 2012 applications of 103 QRs to the Swedish Association of Local Authorities and Regions (SALAR) and also studied the annual reports from the same QRs. After initial data abstraction, the coordinator of each QR was contacted at least twice between June and October 2013 and asked to confirm the accuracy of the data retrieved from the applications and reports.

RESULTS

About 60% of the QRs covered ≥80% of their target population (completeness). Data recorded in Swedish QRs include aspects of disease management (diagnosis, clinical characteristics, treatment and lead times). In addition, some QRs retrieve data on self-reported quality of life (EQ5D, SF-36 and disease-specific measures), lifestyle (smoking) and general health status (World Health Organization performance status, body mass index and blood pressure).

CONCLUSION

Detailed clinical data available in Swedish QRs complement information from government-administered registries and provide an important source not only for assessment and development of quality of care but also for research.

Impaired metabolic control and socio-demographic status in immigrant children at onset of Type 1 diabetes

AIM

The aim of the present study was to compare clinical and socio-demographic conditions at the onset of Type 1 diabetes in children born to immigrant families and children born to Swedish families, and to assess whether those conditions had an impact on metabolic status.

METHODS AND DESIGN

This was an observational nationwide population-based matched cohort study on prospectively recorded registry data of all children with diabetes in Sweden and their families during 2000-2010. Out of a total of 13 415 children from the Swedish Childhood Diabetes Registry (SWEDIABKIDS), 879 children born to immigrant parents were collected. To these we added 2627 children with Swedish-born parents, matched for gender, age and year of onset of Type 1 diabetes.

RESULTS

The proportion of low capillary pH (< 7.30) at onset was higher in the immigrant cohort [25.8% vs. 16.4% in the Swedish cohort (P < 0.001)]. HbA1c was also higher [95 mmol/mol (10.8%) vs. 88 mmol/mol (10.2%), respectively (P < 0.001)]. In a logistic regression model with low pH as the dependent variable, we were unable to reveal any significant association to socio-demographic factors, but the odds ratio for HbA1c was 0.983 (95% CI 0.976-0.991) and for plasma glucose was 0.953 (95% CI 0.933-0.973).

CONCLUSION

Children born to immigrant parents have lower capillary pH and higher HbA1c at diabetes onset. Immigrant families harbour lower socio-demographic living conditions, but this fact does not seem to influence the inferior metabolic condition at diabetes onset.

Equal access to health care may diminish the differences in outcome between native and immigrant patients with type 1 diabetes

BACKGROUND/OBJECTIVE

Previous studies have found that ethnicity influences glycemic control. We hypothesized that differences between Nordic and non-Nordic patients are less pronounced for children with type 1 diabetes in high incidence countries in Northern Europe.

RESEARCH DESIGN AND METHODS

We investigated patients aged 0-15 yr in national pediatric registers in Denmark (D), Iceland (I), Norway (N), and Sweden (S) (2006-2009). Ethnic origin was defined by maternal country of birth as being Nordic or non-Nordic (other countries).

RESULTS

The cohort (n = 11,908, 53.0% boys, onset age 7.7 (3.9) yr, diabetes duration 6.1 (3.6) yr, [mean, (SD)]) comprised 921 (7.7%) non-Nordic patients. The frequencies of non-Nordic patients according to country of residence were: 5.7% (D), 2.7% (I), 5.5% (N), and 9.4% (S). Sex distribution and BMI z-score did not differ between Nordic and non-Nordic patients, but non-Nordic patients were 0.5 yr younger at onset than Nordic patients (p < 0.0006). Non-Nordic patients had a lower number of daily insulin bolus injections and higher daily insulin doses compared to their Nordic peers. Patients of non-Nordic origin had slightly higher HbA1c levels (0.6-2.9 mmol/mol, p < 0.001) and, with the exception of Norway, were less frequently treated with CSII (p = 0.002) after adjusting for confounders.

CONCLUSIONS

The reported differences in glycemic regulation between Nordic and non-Nordic type 1 diabetes children and adolescents in four Nordic countries are diminutive, but persist after accounting for treatment intensity.

Residual beta cell function at diagnosis of type 1 diabetes in children and adolescents varies with gender and season

BACKGROUND

There are seasonal variations and gender differences in incidence of type 1 diabetes (T1D), metabolic control and responses to immune interventions at onset of the disease. We hypothesized that there are seasonal and gender differences in residual insulin secretion already at diagnosis of T1D.

METHODS

In 2005, a national study, the Better Diabetes Diagnosis, was started to classify all newly diagnosed children and adolescents with diabetes. About 95% (3824/4017) of the patients were classified as T1D, and our analyses are based on the patients with T1D.

RESULTS

C-peptide was lower in younger children, 0-10 years of age (0.23 ± 0.20 nmol/L) than in older children, 11-18 years of age (0.34 ± 0.28 nmol/L) (p < 0.000 ). There was a seasonal variation in non-fasting serum C-peptide, significantly correlated to the seasonal variation of diagnosis (p < 0.01). Most children were diagnosed in January, February and March as well as in October when C-peptide was highest, whereas fewer patients were diagnosed in April and May when serum C-peptide was significantly lower (p < 0.01). The seasonal variation of C-peptide was more pronounced in boys than in girls (p < 0.000 and p < 0.01, respectively). Girls had higher C-peptide than boys (p < 0.05), especially in early puberty.

CONCLUSIONS

Both seasonal and gender differences in residual beta cell function exist already at diagnosis of T1D. These observations have consequences for treatment and for randomizing patients in immune intervention clinical trials.